Liquid injection trap with magnetic valve



July 19, 1966 A. J. F. GUILLERMIC 3,261,502

LIQUID INJECTION TRAP WITH MAGNETIC VALVE 2 Sheets-Sheet 1 Filed Nov. 6, 1964 A M4W .v A 1- m//?M- A 1 M vw m= /V" I FW 9 5 MM a M w BY MORGAN, FINNEGAN, DURHAM 8| PINE ATTORNEYS y 1966 A. J. F. GUILLERMIC 3,

LIQUID INJECTION TRAP WITH MAGNETIC VALVE Filed Nov. 6. 1964 2 Sheets-Sheet 2 N or 22a 23a IE 24b INVENTOR ANDRE JOACHIM FRANQOIS GUILLERMIC BY a,7ym,Mu

ATTORNEYS United States Patent 95 23 Claims. (Cl. 222-1) This invention relates to a device for injecting a liquid at a low rate of flow into any desired system.

Industrial practice frequently requires the addition of a liquid into a system at a low flow-rate. The addition may be either intermittent or at regular intervals. A particular example of this is the injection of a liquid into a boiler flue so as to prevent or at least reduce corrosion and soot-deposition. It has been found that known devices for this purpose show certain defects when used at low rates of flow, e.g. of the order of cc./hr., particularly variation in the flow-rate. This is often due to the liquid being oifered a small cross-sectional area of passage, resulting in progressive clogging of the liquid distributors in the devices. Capillarity and viscosity phenomena, and pressure variations which bring about retention effects, may also cause the flow-rate to vary. Moreover, it is difficult to obtain in practice flow-rates below about 150 cc./hr. with the known devices.

The present invention provides a simple and cheap device which does not possess these defects, and is capable of supplying liquid at a very low rate of flow, i.e. down to 10 cc./hr., and with a dosage or injection accuracy of i10%. It consists, in one aspect, of a valve comprising a first body having a hollow passage along its longitudinal axis opening to a recess, entry and overflow passages whose longitudinal axes are co-linear and perpendicular to the longitudinal axis of the first body, and which open to the recess, a second body, movable in the recess of the first body, having a hollow passage along its longitudinal axis of smaller cross-sectional area than the axial passage of the first body, a rod movable in the recess, having one end shaped so as to be capable of sealing the internal end of the axial passage in the second body, and the other end rigidly and co-linearly joined to a rod of magnetisable material movable in the axial passage of the first body, and magnetising means positioned exterior to the first body so as to be capable of controlling the movement of the magnetisable rod.

It consists, in a further aspect, of a means of injecting liquid into a system employing a valve as described above which comprises firstly causing the space defined by the lowest common levels of the entry and overflow passages of the first body and the internal end of the second body to fill with liquid, only then causing the magnetisable rod, and the rod attached thereto, to be moved by employment of the magnetising means so that the internal end of the axial passage in the second body is not sealed, and allowing the liquid in the above-defined space to pass out of the valve into the system through the axial passage of the second body.

It consists, in a still further aspect, of a means of injection of liquid into a system using a plurality of valves of the type described above in which the valves are supplied with liquid by a single pump, and the rods of the respective valves are actuated by means of a single cam driven by the pump, or by means of contacts on the pump shaft, it being provided that the valves all inject liquid into the system outside their respective filling periods.

The space referred to can be varied by movement of the second body in and out of the recess in the first body. Conveniently the inner surface of the recess and the outer surface of at least part of the second body will be threaded so as to allow this movement. The extent of the movement may be assessed by means of a scale attached to the valve.

The magnetising means will usually be a coil wound on the first body. Excitation of this causes the magnetisable rod to be attracted along the axial passage so that more of it is within the zone of influence of the coil or other magnetising means. This rod forms the upper part of a composite rod, the lower part of which is positioned so as to seal the aperture in the second body When the coil etc. is not energised. The aperture and the end of the lower rod will of course be shaped so that they mate together to effectively seal the aperture. For example, the end of the rod may be conical with a corresponding conically-ended aperture in the second body.

The composite rod is so constructed because its upper portion is necessarily of magnetisable material and its lower portion must be resistant to corrosion. The valve that is the subject of the invention is capable of dealing with a great variety of liquids, but it has not been found possible to obtain a satisfactory and economic compromise between a material which is easily magnetised and one which will resist the action of corrosive liquids. The upper part of the composite rod moves in the passage within the first body, and may be made of a material such as soft iron or soft steel, although it is desirable that this material should have some resistance to corrosion since it may be exposed to a corrosive atmosphere. Alternatively, a diaphragm sealing unit may be used to separate the two parts of the rod. The lower part of the composite rod is immersed in the liquid being dealt with, and should therefore be made of a material resistant to corrosion. The nature of this material will depend on the liquid, but a material should be chosen which has the necessary properties of mechanical strength, hardness, etc. It need not be metal, for example if ammonia is being handled, a plastic material, such as polytetrafluoroethylene could be used. However, stainless steel is very satisfactory in many cases. These considerations applying to the lower rod also apply to the other parts of the valve exposed to the liquid.

It is an essential feature of the second embodiment of the invention that the valve space should fill to its maximum level before the passage in the second body is opened by movement of the rod. However, in the case where the rod is moved at regular intervals by periodic excitation of the coil, so as to periodically inject the liquid into the desired system it may not be possible to completely empty the valve space during one movement of the rod. This will occur when the volume injected is small compared to the volume of the valve space. In this case the liquid occupying the valve space is entirely emptied into the system to which the valve is connected in a number of movements, which need not be all of the same duration, depending on the mode of control of excitation of the magnetising coil. Only when the valve space is empty can the supply of liquid to the valve be resumed, for example, if a pump is used to supply the valve with liquid this must be arranged to operate in pulses which begin only when the valve space is empty and the axial passage sealed by the rod, and stopped before the rod moves to cause the liquid to leave the now full valve space.

A stop may be provided to limit the upward travel of the composite rod when energised by the coil. This is necessary when the valve space is adjusted to a maximum, so as to ensure a cross-section of passage which is approximately constant, particularly when the valve space is not emptied by one movement of the rod. The stop ensures that the rod is lifted by a constant height, and therefore that a given fraction of the liquid in the valve space flows out per single movement. As stated above, the period of excitation of the coil may vary, and thus the quantity of liquid flowing out will vary according to this period. The stop provides that for a given period the quantity flowing out will remain constant.

For regular and periodic injection of liquid into a system, it is envisaged that the magnetising means would be actuated automatically. For a single injection, or for irregular injections, there is no reason why the injection valve should not be operated manually, provided that the valve space is full of liquid. However automatic operation is much more convenient. One way of providing this is to have a cam driven by the means supplying the liquid to the injection valve e.g. a pump. The cam would be driven from the pump shaft, and would be so shaped as to determine the respective times of excitation of the coil, and hence the times of lift of the composite rod. This aspect of cam shape will be well understood by those skilled in the art, but it is sufficient to point out that the cam shape may provide for emptying of the valve space by either one or more movements of the rod.

A particular system may require the use of a number of the above injection valves, which may be supplied from one pump or other means of supply. The output of this pump must be, of course, not less than the quantity of liquid per injection supplied by the valve having the biggest outflow, assuming that the outflows of the various valves are unequal. If the operation of the valves is by means of a cam acting on a number of electrical contacts, then the angular displacement of the contacts is preferably chosen so as to reduce the power employed. Preferably also, there are as many contacts as there are valves. The cam must be shaped so that the contacts are all made outside the filling periods of their respective valves, that is, when the pump is not operating on them.

Instead of cam operation, contacts may be provided on the pump shaft to operate the electrical contacts, provided always that the criterion just referred to is met.

Reference is now made, by way of example only, to the accompanying drawings, which illustrates a specific embodiment of an injection valve according to the invention and aspects of its control and the use of a number of these injection valves. In the drawings:

FIG. 1 shows a section, in vertical elevation, of the injection valve, according to the specific embodiment,

FIG. 2 illustrates a liquid injection system using four injection valves according to the invention,

FIG. 3 represents a cam and the associated electrical contacts which can be used to control the four injection valves referred to in FIG. 2,

FIG. 4 represents a further cam, and its associated contacts which can be used to energise the magnetising coil of a single valve according to the invention so that the rod will be raised, and liquid will flow out of the valve, for two periods of different duration, both comprised within the interval between two successive operations of the filling pump or other means, and

FIG. 5 is a schematic diagram illustrating the electrical connections which may be established for the control of four traps located on the same circuit and with staggered operation in relation to one another, as illustrated in FIGURE 2.

In FIG. 1, the entry passage 1 and the overflow passage 2 are on the same level with reference to the longitudinal axis of the valve. Liquid flows in through 1 due to the action of a pump (not shown), and any excess over that required to fill the valve space 2a flows out through 2. Valve space 2a is defined by the lowest levels of passages 1 and 2, and the top 3 of the second body 4. Space 2a may be varied by moving body 4 on the internal threading 5 of the component part 6 of the valve. Body 4 is provided with a knurled ring 10, and a graduated scale a is attached to 6 so as to provide an indication of the volume of valve space 2a. Body 4 also has an axial passage 4a, which is the exit passage of the valve. Part 6,

which is integral with passages 1 and 2, is sealed to a first body 14 by a seal 15, so that the assembly is leakproof. Body 14 has an axial passage 14a of greater cross-sectional area than that of 4a, and in this passage and in space 2a moves a composite rod made of an upper soft steel rod 8 rigidly screwed to a polytetrafiuoroethylene (P.T.F.E.) rod 7. The lower end 11 of rod 7 is so shaped that it fits, when in its lowest position, into the top of passage 4a, which is shaped to accept it. Rod 7 actually moves largely in space 2a, and rod 8 largely in passage 14a. The upper part of body 14 is shaped to form a collar, around which is placed a coil 9, which exerts a magnetising influence on the rod 8 when a current is passed through connections 9a and 9b. An optional screw 12 provides a stop at 13 to the upper travel of the rod 8 for the reason previously described.

The whole valve, apart from rod 8, may suitably be made of P.T.F.E., particularly if a liquid such as 20% aqueous ammonia solution is being dealt with. A seal between part 6 and body 4 is not shown for the sake of simplicity.

The assembly of FIG. 1 is completed by a breather 16, which may communicate with a buffer tank 17, optionally equipped with a vacuum release valve 18.

In FIG. 2, liquid stored in a tank 19 is distributed by means of a pump 20 delivering to four injection points 21, 22, 23 and 24, where injection occurs through valves 21a, 22a, 23a, and 24a. A pressure regulator 25 makes it possible to ensure filling of the four valves whatever the delivery time of the pump 20. It will be understood that pump 20 may comprise any suitable pump capable of delivering a pulsed output, for example, a single acting, reciprocating pump.

When there are a number of injection points, such as illustrated in FIGURE 2, pump 20 is driven by a motor 29 which also drives a speed reducing gear 30 acting in turn on a cam member, indicated generally by reference numeral 31. The ratio of the speeds of the two shafts of the reducing gear is l/n, where n is the number of contacts to be controlled.

Where there is only one injection point, reducing gear 30 may be eliminated and the cam 31 may be fixed either on the shaft of the motor or on the shaft of the pump, since both shafts rotate at the same angular speed.

In FIG. 3, a cam 26 has a boss 26a which successively actuates four electrical micro-switch contacts 21b, 22b, 23b, and 2417. This cam may be driven by a speed reducing gear so that it turns one-quarter of a revolution for each rotation of the motor driving the pump, the cam being mounted so that the actuation of the contacts 21b to 24b always occurs outside the period of delivery of the pump to any of the valves which are being operated by closure of those contacts.

It is essential that the period of activity of the pump (delivery stroke) should correspond to an angle alpha such that the boss 26a cannot act on two successive contacts, which in practice means alpha=360/2n degrees, if n is the number of contacts to be controlled.

The cam 27 of FIG. 4 actuates a single micro-switch contact 28, and is driven directly 'by the pump-motor shaft. Although the time of lift of the rod 7 is chosen such that trouble due to choking is avoided, in this case the duration of closure of contact 28 by the first boss 27a of cam 27 is sufficiently small for the space 2a not to be emptied completely during this first phase of excitation of coil 9. The second boss 27b provides for a much longer closure of contact 28 so that the space 2a may be emptied completely during this second phase, and before the pump acts again during the remainder of rotation of cam 27 when the contacts 28 are constantly open.

In the particular case of controlling a single contact by several bosses of one and the same cam, as illustrated in FIGURE 4, it is obviously necessary for these to be distributed over a semi-circumference if. the cam is locked directly on the shaft of the pump and in such a way that the active period of the pump (i.e., delivery of the liquid) corresponds to the passage of the cylindrical part of radius r in front of the contact 28 which is then in the open position.

Finally, FIGURE 5 shows the electrical connections which are established for the control of four traps located on the same circuit and with staggered operation in relation to one another. Of course, it will be obvious to those of ordinary skill in the art that several traps can be branched from one another if it should be necessary to coincide several operations which take place at different points in the liquid circuit.

Although the valve specifically embodied is cylindrical in shape, there is no reason Why the valve of the invention should not be of any convenient shape. For example, the first body might be spherical, with a recess into which a tubular body incorporating the entry and overflow passages would fit.

I claim:

1. A trap including valve means for supplying discrete amounts of liquid to a desired system, comprising: a first body having a hollow passage along its longitudinal axis; a second body spaced from said first body, said second body having an outlet passage along its longitudinal axis in substantial alignment with the axial passage of said first body; said first and second bodies separated by a recess in co-axial alignment with their longitudinal axes; entry .and overflow passages opening to said recess at a common level; said recess being adjustable along said longitudinal axes of said first and second bodies; said recess and said level of said entry and overflow passages defining a liquid-containing chamber of predetermined volume; a rod member normally extending through said recess, one end of said rod member adapted to normally seal the internal end of the outlet passage in said second body, the other end of said rod member being slidably received in the axial passage of said first body, at least a portion of said rod member formed of magnetisable material; and magnetising means positioned exterior to said first body, said magnetising means adapted to control the movement of said magnetisable rod member into and out of sealing engagement with said outlet passage whereby discrete amounts of liquid may be emitted from said liquid containing chamber through said outlet passage to said desired system.

2. A trap according to claim 1 wherein said recess is formed by a hollow member adjustably integrally mounted to each of said first and second bodies and extending co-axially therebetween, and wherein said liquid containing chamber is defined by the lowest level of said entry and overflow passages and the internal end of said second body portion of said valve.

3. A trap according to claim 1 wherein said outlet passage of said second body is of smaller cross-sectional area than said axial passage of said first body, and wherein said one end of said rod member is generally conically shaped so as to be normally sealingly received by said outlet passage of said second body.

4. A trap according to claim 1 including adjustable stop means provided in the axial passage of said first body so as to limit the travel of said rod member therein.

5. A trap according to claim 1 wherein said magnetisable material forming a portion of said rod member is a corrosion resistant material.

6. A trap according to claim 1 wherein at least a portion of said rod member is composed of a corrosion resistant material.

7. A trap according to claim 1 wherein said first and second bodies are substantially cylindrical, and said rod member and said axial passages of said first and second bodies are of substantially circular cross-section.

8. A trap according to claim 1 wherein said entry and overflow passages are of substantially circular cross-section.

9. A trap according to claim 1 wherein said first and second bodies are composed substantially of corrosion-resistant material.

. 10. A trap according to claim 9 wherein said corrosionresistant material is polytetrafiuoroethylene.

11. A trap according to claim 10 wherein the corrosion-resistant material is stainless steel.

12. A trap according to claim 1 including means for actuating said magnetising means at predetermined intervals whereby said liquid containing chamber is emptied upon a predetermined number of movements of said rod member.

13. A trap according to claim 1 including means for actuating said magnetizing means so as to empty said liquid-containing chamber by a single movement of said rod member.

14. A system for supplying discrete amounts of liquid to a desired system, comprising: a plurality of traps, each of said traps including valve means comprising a first body having a hollow passage along its longitudinal axis, a second body spaced from said first body, said second body having an outlet passage along its longitudinal axis in substantial alignment with the axial passage of said first body, said first and second bodies separated by a recess in co-axial alignment with their longitudinal axes, entry and overflow passages opening to said recess at a common level, said recess being adjustable along said longitudinal taxes of said first and second bodies, said recess and said level of said entry and overflow passages defining a liquidicontaining chamber of predetermined volume, a rod member normally extending through said recess, one end of said rod member adapted to norm-ally seal the internal end of the outlet passage in said second body, the other end of said rod member being slidably received in the axial passage of said first body, at least a portion of said rod member formed of magnetisable material, and magnetising means positioned exterior to said first body adapted to control the movement of said magnetisable rod member into and out of sealing engagement with said outlet passage; intermittently acting pump means for filling each of said traps with liquid; pressure regulator means; and means for automatically actuating said magnetising means of each of said traps in timed sequence with said pump means whereby said valve means inject liquid to said desired system outside their respective filling periods.

15. A system according to claim 14 wherein said pump means includes a rotary drive said means for actuating said magnetising means includes a cam also driven by said rotary drive.

16. A system according to claim 14 wherein said cam means are driven by means of electrical contact means provided on the rotating element of said rotary drive.

17. A method of supplying discrete amounts of liquid to a system, comprising: providing a trap having a liquidcontaining chamber of variable capacity, said chamber having an outlet passage therein, setting said chamber so as to contain a predetermined volume of liquid, sealing said outlet passage with a magnetizable rod member movably mounted within said chamber, positioning magnetizing means exteriorly of said liquid-containing chamber, filling said liquid-containing chamber withsaid predetermined volume of liquid, and thereafter passing said liquid out of said outlet passage in said chamber by actuating said magnetizing means so as to move said rod member out of sealing engagement with said outlet passage.

18. A method aocording to claim 17, including pumping said liquid to said liquid-containing chamber by an intermittently acting pump.

19. A method according to claim 17, including passing said liquid out of said liquid-containing chamber by a plurality of movements of said rod member.

' 20. A method according to claim 19, including removing unequal fractions of the liquid contained in said chamber With each movement of said rod member.

21. A method according to claim 19, including actuating said rod member by means of a cam operatively connected to the liquid supply means.

22. A method of injecton of liquid into a system, comprising: providing a plurality of traps, each of said traps having a liquid-containing chamber of variable capacity, said chamber having an outlet passage therein, setting each of said chambers so as to contain a predetermined volume of liquid, sealing said outlet passages of each of said chambers with a magnetizable rod member movably mounted Within said chamber, positioning magnetizing means exteriorly of each of said chambers, pumping liquid to each of said traps by means of a single pump so as to fill each of said liquid-containing chambers With their respective predetermined volumes of liquid, said liquid being pumped to said traps only when said liquidcontaining chamber thereof is empty, and passing said liquid out of said outlet passages in each of the respective chambers by actuating the respective magnetizing means so as to move said rod members out of sealing engagement with said outlet passages, each of said magnetizing means being actuated by means of a single cam driven by said pump.

23. A method of injection of liquid into a system, comprising: providing a plurality of traps, each of said traps having a liquid-containing chamber of variable capacity, said chamber having an outlet passage therein, setting each of said chambers so as to contain a predetermined volume of liquid, seal-ing said outlet passages of each of said chambers with a magnetizable rod member movably mounted within said chamber, positioning magnetizing means exteriorly of each of said chambers, pumping liquid to each of said traps by means of a single pump so as to fill each of said liquid-containing chambers with their respective predetermined volumes of liquid, said liquid being pumped to said traps only when said liquidcontaining chamber thereof is empty, and passing said liquid out of each of said outlet passages in each of the respective chambers by actuating the respective magnetizing means so as to move said rod members out of sealing engagement with said outlet passages, each of said magnetizing means being actuated by means of a single cam driven by means of contacts mounted on the pump shaft.

References Cited by the Examiner UNITED STATES PATENTS 2,965,268 12/1960 Bauerlein 222504 X ROBERT B. REEVES, Primary Examiner.

HADD S. LANE, Examiner. 

1. A TRAP INCLUDING VALVE MEANS FOR SUPPLYING DISCRETE AMOUNTS OF LIQUID TO A DESIRED SYSTEM, COMPRISING: A FIRST BODY HAVING A HOLLOW PASSAGE ALONG ITS LONGITUDINAL AXIS; A SECOND BODY SPACED FROM SAID FIRST BODY, SAID SECOND BODY HAVING AN OUTLET PASSAGE ALONG ITS LONGITUDINAL AXIS IN SUBSTANTIAL ALIGNMENT WITH THE AXIAL PASSAGE OF SAID FIRST BODY; SAID FIRST AND SECOND BODIES SEPARATED BY A RECESS IN CO-AXIAL ALIGNMENT WITH THEIR LONGITUDINAL AXES; ENTRY AND OVERFLOW PASSAGES OPENING TO SAID RECESS AT A COMMON LEVEL; AND RECESS BEING ADJUSTABLE ALONG SAID LONGITUDINAL AXES OF SAID FIRST AND SECOND BODIES; AND RECESS AND SAID LEVEL OF SAID ENTRY AND OVERFLOW PASSAGES DEFINING A LIQUID-CONTAINING CHAMBER OF PREDETERMINED VOLUME; A ROD MEMBER NORMALLY EXTENDING THROUGH SAID RECESS, ONE END OF SAID ROD MEMBER ADAPTED TO NORMALLY SEAL THE INTERNAL END OF THE OUTLET PASSAGE IN SAID SECOND BODY, THE OTHER END OF SAID ROD MEMBER BEING SLIDABLY RECEIVED IN THE AXIAL PASSAGE OF SAID FIRST BODY, AT LEAST A PORTION OF SAID ROD MEMBER FORMED OF MAGNETISABLE MATERIAL; AND MAGNETISING MEANS POSITIONED EXTERIOR TO SAID FIRST BODY, SAID MAGNETISING MEANS ADAPTED TO CONTROL THE MOVEMENT OF SAID MAGNETISABLE ROD MEMBER INTO AND OUT OF SEALING ENGAGEMENT WITH SAID OUTLET PASSAGE WHEREBY DISCRETE AMOUNTS OF LIQUID MAY BE EMITTED FROM SAID LIQUID CONTAINING CHAMBER THROUGH SAID OUTLET PASSAGE TO SAID DESIRED SYSTEM.
 14. A SYSTEM FOR SUPPLYING DISCRETE AMOUNTS OF LIQUID TO A DESIRED SYSTEM, COMPRISING: A PLURALITY OF TRAPS, EACH OF SAID TRAPS INCLUDING VALVE MEANS COMPRISING A FIRST BODY HAVING A HOLLOW PASSAGE ALONG ITS LONGITUDINAL AXIS, A SECOND BODY SPACED FROM SAID FIRST BODY, SAID SECOND BODY HAVING AN OUTLET PASSAGE ALONG ITS LONGITUDINAL AXIS IN SUBSTANTIAL ALIGNMENT WITH THE AXIAL PASSAGE OF SAID FIRST BODY, SAID FIRST AND SECOND BODIES SEPARATED BY A RECESS IN CO-AXIAL ALIGNMENT WITH THEIR LONGITUDINAL AXES, ENTRY AND OVERFLOW PASSAGES OPENING TO SAID RECESS AT A COMMON LEVEL, SAID RECESS BEING ADJUSTABLE ALONG SAID LONGITUDINAL AXES OF SAID FIRST AND SECOND BODIES, SAID RECESS AND SAID LEVEL OF SAID ENTRY AND OVERFLOW PASSAGES DEFINING A LIQUID-CONTAINING CHAMBER OF PREDETERMINED VOLUME, A ROD MEMBER NORMALLY EXTENDING THROUGH SAID RECESS, ONE END OF SAID ROD MEMBER ADAPTED TO NORMALLY SAID THE INTERNAL END OF THE OUTLET PASSAGE IN SAID SECOND BODY, THE OTHER END OF SAID ROD MEMBER BEING SLIDABLY RECEIVED IN THE AXIAL PASSAGE OF SAID FIRST BODY, AT LEAST A PORTION OF SAID ROD MEMBER FORMED OF MAGNETISABLE MATERIAL, AND MAGNETISING MEANS POSITIONED EXTERIOR TO SAID FIRST BODY ADAPTED TO CONTROL THE MOVEMENT OF SAID MAGNETISABLE ROD MEMBER INTO AND OUT OF SEALING ENGAGEMENT WITH SAID OUTLET PASSAGE; INTERMITTENTLY ACTING PUMP MEANS FOR FILLING EACH OF SAID TRAPS WITH LIQUID; PRESSURE REGULATOR MEANS; AND MEANS FOR AUTOMATICALLY ACTUATING SAID MAGNETISING MEANS OF EACH OF SAID TRAPS IN TIMED SEQUENCE WITH SAID PUMP MEANS WHEREBY SAID VALVE MEANS INJECT LIQUID TO SAID DESIRED SYSTEM OUTSIDE THEIR RESPECTIVE FILLING PERIODS. 